1. Field of the Invention
The present invention relates to an organic/inorganic hybrid material, and in particular relates to an organic/inorganic hybrid material having an inorganic platelet network structure.
2. Description of the Related Art
Organic/inorganic hybrid materials consisting of a combination of an inorganic material and an organic phase combine the properties of organic and inorganic materials. Inorganic materials such as glass, fiber, clay, and carbon black are typically added to an organic polymer as a filler or as a reinforcing agent to improve physical properties and reduce production cost. The effectiveness of an inorganic filler is generally determined by the degree of dispersion of the inorganic filler in the polymer matrix. By conventional mechanical blending, only a micro-scale dispersion of the inorganic filler can be achieved and improvement in physical properties is limited. Using a novel organic/inorganic nano-hybrid technique, an inorganic filler can be dispersed in an organic matrix at a nano-scale, greatly improving physical properties due to the greater contact surface between the organic phase and inorganic phase. A nano-hybrid material is characterized by high transparency, high thermal resistance, low coefficient of thermal expansion, and excellent mechanical properties. In order to increase the physical properties, the key issue in developing hybrid materials is to increase the amount of inorganic filler present in the hybrid.
A typical example of nanoclay/polymer material is clay/nylon nanocomposite as disclosed in U.S. Pat. Nos. 5,102,948, 5,206,284, 5,248,720, and 5414042. In one approach, smectite clay is modified to an organoclay by ion exchange with quaternary ammonium compounds to improve dispersibility in an organic solvent. The organoclay is then mixed with a polymer material in the organic solvent to provide a composite. The composite thus prepared has an inorganic content of up to 20 wt %. In another approach, the clay is intercalated with a water soluble polymer to improve dispersibility, and then dispersed in a polymer matrix. The composite prepared by this approach has a high inorganic content of 30 wt % or above. However, both of the two approaches involve the dispersion of clay in an organic matrix, and therefore when inorganic content is increased, the material will inevitably become opaque and brittle due to insufficient polymer content.
Accordingly, it is highly desirable to increase inorganic content to improve physical properties while maintaining transparency and flexibility of organic/inorganic hybrid materials.